Power & Boot
Power Supply Specifications
The Rhino Core Q64 smart module uses the Qualcomm PMIC power solution (PM7325 / PM7350C / PM7250B) and is powered through board-to-board connectors.
| Signal | Type | Voltage Range | Description |
|---|---|---|---|
| VBATT | Main power input | 3.5V ~ 4.2V | Main power supply for the core board, typically 3.8V |
| USB_VBUS | USB charging input | 3.7V ~ 12.6V | Supports QC5.0 fast charging |
Power Capacity Requirements
With the CPU and GPU at full load, the current can reach up to 7A. When powered by battery, ensure sufficient capacitance on VBAT on the carrier board (at least two 47μF capacitors recommended) and protection with a 5.1V / 500mW TVS diode.
Power Outputs
The core board provides multiple regulated outputs through the PMIC for carrier board peripherals:
| Output Signal | Voltage | Description |
|---|---|---|
| VREG_BOB1 | Buck/Boost adjustable | Supplies the CODEC IC |
| VREG_S1B_1P856 | 1.8V | General-purpose 1.8V output |
| VREG_L6C_2P96 | 2.96V / 1.8V | TF card IO power |
| VREG_L12C_1P8 | 1.8V | General-purpose 1.8V output |
| VREG_L8C_1P8 | 1.8V | IO power |
| VREG_L3C_3P0 | 3.0V | General-purpose 3V output |
| VREG_L7C_3P0 | 3.0V | General-purpose 3V output |
| VREG_L18B_1P8 | 1.8V | General-purpose 1.8V output |
| VREG_L11C_2P8 | 2.8V | General-purpose 2.8V output |
| VREG_L9C_2P96 | 1.8V / 2.95V | TF card power |
| VPH_PWR | 3.6V | General-purpose 3.6V output |
Clock Outputs
The core board provides the following clock signals:
| Signal | Frequency | Level | Description |
|---|---|---|---|
| PMK_CLK_NFC | 19.2MHz | 1.2V | NFC clock |
| SLEEP_CLK | 32.7645kHz | 1.8V | Wi-Fi sleep clock |
Power Sequencing
The core board integrates the Qualcomm PMIC power management chip, and the power-up sequence is automatically managed by the PMIC. The carrier board design does not need to handle the core board's power-up sequence separately; it only needs to provide stable VBATT power.
Reset Signals
| Signal | Type | Active Level | Description |
|---|---|---|---|
| PM_RESIN_N | Input | Active low | Reset signal; pulling low resets the core board |
Power On/Off Control
The core board supports two power-on methods: key power on/off and auto power-on on power-up.
| Signal | Type | Active Level | Description |
|---|---|---|---|
| KPD_PWR_N | Input | Active low | Power key signal |
In the carrier board design, it is recommended to connect KPD_PWR_N to ground through a key: short press to power on, long press to force power off.
Auto Power-on Notes
Due to the onboard PM7250B, automatic power-on cannot be triggered via the PM_CBL_PWR_N signal (J1 Pin 42 is NC). If power-on on power-up is required, design a trigger circuit to satisfy the automatic power-on logic.
Boot Media
The core board boots from eMMC by default. The system firmware is flashed to the onboard eMMC storage, and the bootloader is loaded from eMMC after power-up.
Flashing Mode
| Signal | Active Level | Description |
|---|---|---|
| FORCE_USB_BOOT | Active high | Force download mode enable signal |
Steps to enter flashing mode:
- Pull the FORCE_USB_BOOT signal high
- Power on the core board
- Connect to the host via USB and use the Qualcomm flashing tool to flash the firmware
Flashing Circuit Design
The force download mode should follow the recommended circuit design in the specifications. The FORCE_USB_BOOT signal is located on J3 Pin 23.
RTC Backup Power
| Signal | Type | Description |
|---|---|---|
| VCOIN | Input/Output | RTC backup power input |
When VBATT is disconnected, VCOIN can be used to provide backup power to the RTC. An external large capacitor or coin cell battery is recommended. Power consumption after VBATT is disconnected is approximately 10μA; choose an appropriate capacitor or battery according to your needs. If lower RTC current is required, it is recommended to use a tuned external RTC chip on the carrier board.